Method of electrochemically detecting target substance, method of electrochemically detecting analyte, test chip, and detection set

Abstract

The present invention provides a method for electrochemically detecting a target substance and a method for electrochemically detecting an analyte using a probe holding substrate with a probe for trapping a target substance or an analyte held on the substrate body as well as a test chip and a detection set using the above detection methods.

What is claimed is: 
     
       1. A method of electrochemically detecting a target substance containing a labeling substance, comprising:
 (1-1) bringing the target substance containing the labeling substance into contact with a probe holding substrate in which a probe for trapping the target substance containing the labeling substance is held on the probe holding substrate and allowing the target substance containing the labeling substance to be trapped by the probe; 
 (1-2) detaching the labeling substance, the target substance or a moiety which is a part of the target substance and contains the labeling substance from the probe holding substrate obtained in the process (1-1) and attracting to a working electrode in which a trapping substance for trapping the labeling substance, the target substance or the moiety which is a part of the target substance and contains the labeling substance is not present, wherein the working electrode and the probe holding substrate are arranged so as to be opposed to each other with a space therebetween; and 
 (1-3) electrochemically detecting the labeling substance, the target substance or the moiety which is a part of the target substance and contains the labeling substance which has been attracted to the working electrode in the process (1-2), 
 wherein the probe holding substrate in the process (1-1) is a probe holding substrate in which the probe for trapping the target substance containing the labeling substance is held on a substrate body through a holder, and 
 wherein the holder has a first layer composed of a metal that is dissolved in a solution or an alloy thereof and the probe which has trapped the target substance containing the labeling substance is detached from the substrate body of the probe holding substrate by bringing the solution into contact with the holder in the process (1-2). 
 
     
     
       2. The method according to  claim 1 , wherein the first layer is comprised of gold and palladium and the solution is a solution containing iodine or an iodide. 
     
     
       3. The method according to  claim 1 , wherein the labeling substance, the target substance or a moiety which is a part of the target substance and contains the labeling substance is attracted to the working electrode in which the trapping substance is not present by differences in polarity in the process (1-2). 
     
     
       4. The method according to  claim 1 , wherein the labeling substance, the target substance or a moiety which is a part of the target substance and contains the labeling substance is attracted to the working electrode in which the trapping substance is not present by electrophoresis in the process (1-2). 
     
     
       5. The method according to  claim 1 , wherein the labeling substance is an electrochemically or photochemically active substance. 
     
     
       6. A method of electrochemically detecting a target substance containing a labeling substance, comprising:
 (1-1) bringing the target substance containing the labeling substance into contact with a probe holding substrate in which a probe for trapping the target substance containing the labeling substance is held on the probe holding substrate and allowing the target substance containing the labeling substance to be trapped by the probe; 
 (1-2) detaching the labeling substance, the target substance or a moiety which is a part of the target substance and contains the labeling substance from the probe holding substrate obtained in the process (1-1) and attracting to a working electrode in which a trapping substance for trapping the labeling substance, the target substance or the moiety which is a part of the target substance and contains the labeling substance is not present, wherein the working electrode and the probe holding substrate are arranged so as to be opposed to each other with a space therebetween; and 
 (1-3) electrochemically detecting the labeling substance, the target substance or the moiety which is a part of the target substance and contains the labeling substance which has been attracted to the working electrode in the process (1-2), 
 wherein the probe holding substrate in the process (1-1) is a probe holding substrate in which the probe for trapping the target substance containing the labeling substance is held on a substrate body through a holder, and 
 wherein the holder has a first layer composed of a metal that is dissolved in a solution or an alloy thereof and a second layer which is provided among the first layer and the substrate body and makes the first layer stick to the substrate body, and the probe which has trapped the target substance containing the labeling substance is detached from the substrate body of the probe holding substrate by bringing the solution into contact with the holder in the process (1-2). 
 
     
     
       7. The method according to  claim 6 , wherein the second layer is comprised of a substance that is selected from the group consisting of platinum, palladium, titanium, chromium, nickel, indium tin oxide, and indium oxide, and is different from the substances for forming the first layer. 
     
     
       8. The method according to  claim 6 , wherein the first layer is comprised of gold and palladium and the solution is a solution containing iodine or an iodide. 
     
     
       9. The method according to  claim 6 , wherein the labeling substance, the target substance or a moiety which is a part of the target substance and contains the labeling substance is attracted to the working electrode in which the trapping substance is not present by differences in polarity in the process (1-2). 
     
     
       10. The method according to  claim 6 , wherein the labeling substance, the target substance or a moiety which is a part of the target substance and contains the labeling substance is attracted to the working electrode in which the trapping substance is not present by electrophoresis in the process (1-2). 
     
     
       11. The method according to  claim 6 , wherein the labeling substance is an electrochemically or photochemically active substance.